Electric heater.



.. W. L .5?, PSON ELECTRVC HEATER.

APPLICANOM man API-1.8, :915.A

21 25254n Patented Jan.16,1917.

2 SHEETS-*SHEET l.

(7mm u i015 [Tommy ELECTRIC HEATERxA APPLICAUON FILED APR. 8. i916.

Patented Jim. 16, E917.

2 SHEETS-*SHEET 2.

In uma/om? A V( /Df/aso/v UTE. P585 0/1/ @Afm V UnnrED sTArEs rgrENT oEEioE.

ALBERT W. PERSON AND JULIUS E. PERSON. OF HARVARD, NEBRASKA.

l ELECTRIC HEATER.

` Specification of Letters Patent.

Patented Jan. 16,1917.

To ZZ lwhom t may concern I Be it known that we, ALBERT W. PERSON and JULios E. Person, citizens of the wherein a series of heating coils are provided extending in parallel relation.

The general object of the invention is the provision of an electricheater built up of a series of units or sections so that heaters of various sizes may be formed by decreasing or increasing the number of units.

A further object of the invention is to so form the units that when placed'together,'

grooves or channels will be formed between any two sections or units, the grooves or channels being of suitable size and shape to receive the heating coils, and still another object in this connection is t0 provide the sections with surface openings or notches so that when the sections are placed together, openings for the radiation of heat will be provided in the completed element.

i still further object is to provide means to secu-re perfect alinement of the channels and surface openings so that the surface of the heater will be perfectly flat, and the notches which form the openings for the radiation of heat will he kept in perfect alinement, and for this purpose to provide each unit with means for interlocking enga gement with the next adjacent unit.

further object is to provide means at the ends oi? the units whereby when the units are assembled the wires leading from one set of coils to another set of coils may be arranged so that alternate coils are en ygaged with each other. Y

A further object is to so construct the units and the completed heating element formed by combining the units that it may he arranged either for single or three-heat wiring, means being provided whereby an even distribution of heat is obtained either for high, low, or medium heating. By using alternate coils only for medium heat, or coils in series for low heat, and using the coils in two sets, each set being in series and the two sets of coils being in parallel.

A further object is to rprovide heating units and coils which may be readily used in dili'erent sizes of heaters by mere ,duplication of one size of heating section or unit, and in this connection to provide a heater which is particularly adapted for toasters, hot-plates, stoves and ranges, ovens, broilers, grills, etc.

Other objects will appear in the course of the following description.

Our' invention is illustrated' in the accompanying drawings, wherein:

moved; Fig. 2 is a transverse sectional view on the line 2-2 of Fig. 1;- Fig. 3 is a sectional view on the line 3--3 of Fig. 1; Fig. 4 is a perspective view of one of the units detached; Fig. 5 is a perspective view of a number of units assembled; Fig. 6 is a top plan viewl of the unit shown in Fig. 4; Fig. 7 is a section on the line 7-7 of Fig. 6.

Our improved heater, as before stated, is formed of a series 'of units one of which is illustrated in Fig. 4 and designated 10. Each unit has a relatively wide base 11, a longitudinally extending semi-circular channel 1 above the base and on each side of -the medium web ot' the unit, and a relatively top iange, 13 having the same length as the base and the samejvidth as the base but being cut out or notched at a plurality of points. as at 111, the edge wallsof the notches being beveled and the notches being relatively long.' At the ends, each unit is formed with an outwardly projecting iug 15. All of A.

the units are of the same character, except Athe end units 103'. in which the channel 12 ducting; material formed to provide a base ll `troni which entends an upwardly projecting; rib i3 which is tapered toward its lupper edge, this rib being provided adjais further pointed out that by forming` the units. with' interlocking; tenons and recesses the units cannot shift longitudinally or Vern tically upon each other but that the units serve to support each other and there is no chance for the units becoming displaced.

lt will be seen troni 5 that when the units are placed tog-ether side by side with the edge :l'aces the bases in contact with each other, the channels l2 will coact with each other to provide a longitudinally ei;- tendine chainber while the notches will coact to provide a series ot longitudinally extending` sic-ts or radiation openings which open into the channels l2. rlhere will tous be provided without regard to the tace ot the heating elernent,4 a sectional slab having a series bores or chambers extending?)h longitudinally through it7 spaced troni eac.` other, with 'c sl or radiatn l openings entending1 down Y nto these bores7 and the ends of this slab will be provided with a plurality of outward-ly projecting1 lugs l5 disposed vone between each pail? oit bores or channels.` These units l@ to be niade ot porcelain or other like non-conclue tive materiaia The `several units' l0 which together torni the completed` slab or heating1 element ina'y be connected to each other and held'toether in any suitable inannera tor instance, by a trarne9 surrounding and supporting the several elements. @ne 'forni ot this support for the heatingl elements will be described later. Disposed within the channels torined by the grooves l2 are a'plurality ot heating coils l@ of any usual or suit-able character,

these coils as l lustrated in l l being disposed beneath the openings orinefd by the notches lll.. in order to provide for securing a medium, a-low.) and a high heat, is necessary that the several coils should be connected eachothen as indicated in Fig. l.

For the purpose distinguishingl between the several coils E designate one set ot coi`s as a, and another set and n :n 5` it will be seen that one coii c c connectel by a wire l? which passes over two of the -lugs l5 to the nent adja ent coil belonging to the a seriesu while the coils are connected by wires l? which pass beneath the lugs l5. dit one end of the *heating elements are the binding screws 18 and i9, the binding screw 18 engaging with the tirst coil a while the binding screw 19 engages with the first coil Z) of' the series of coils a and b. A switch it is provided having a binding` screw 20 from which a conductor wire or other suitable conductor passes to the binding,` screw i8 while the binding screw 2l of theswitch is connected by means ot a wire or otherv suitable conductor to the binding screw 19.

At the opposite corner ot' the slab formed ot the series ot sections there is a binding screw 22 to which the last coil of the series Z) is connected and to which the last coil oit the series L is connected, and from this screw 22 extends a wire 23 which extends to the binding screw 2i on lthe switch. y'Wires 25 and 26 lead to a source of current, the wire 25 being engaged with the binding screw 27 while the wire 26 is connected to the binding screw 2l. Switch arins are pro- "vided, whereby the wire 25 may be elec trically connected either to the bindingpost' or to the binding` post 20, or whereby the post 2l ina-y be connected to the post 2li or disconnected therefrom. By this means the coils inay be placed either in series or alten nate coils may be placed in parallel with each other, or only one set coils may be heated. This forni ot switch is of a well lrnown type hence requires no speciic description ot the construction.

lin order to hold these sections or units to each other in order to secure perfect aline; ment ot the grooves and surface openings,

we hays provided recesses that dowel or tit into each other so as to interlock one unit 'with another. These recesses in the side faces of the units are designated 29, while the projections or dowels are designated 30. rthese .recesses are preferably triangular in cross section and have inwardly converging sidel waflls7 while the projections or dowels,

formed to tit these recessesv and side walls. this means we secure the perfect alinenient of the sections so that the upper tace ot the slab so torn/red will be perfectly and the notches liof tl-ielsections which town-the openingsl for the radiation ot heat in the completed elen'ient ot the slab will be lrept in perfect alinenient. Under these circumstances this heater or Vslab formedr of sections as before described9 should be used in connection with a sub-base which is desi nated 3l andillustrated in 2. AThis sub-base is niade ot a composition which resists the passage ot lie-at by conductancea and. et' such inateriai that it will endure teinperatres sufficiently high 'for all practi cal purposes. As illustrated,this sub-base is rectangular in torni and the side walls are toi-ined to provide a ledge 32 upon which the ends of the sectionsrest, this ledge extending` entirely around the sub-base, thus providing a dead air space below the slab foi-ined ot the sections 10. W'hen the heating element formed of the sections is intended to be used in a toaster, oven, grill or broiler, it is used without the sub-base, the sections or units of the element being clamped together in any suitable manner. 'hen, however, it is'used for a hot-plate, range or like structure, then the sub-base is to be used.

It is evident that a heating element consi'ucted in accordance Vith this invention has all the advantages of the open coil type ot heater with the additional advantage of oti'ering protection to the heating coils as they are held irnily in place and to a large extent housed. rlhe completed slab or heatingelement is easy to build, and the size of the slab or element may be varied even where only one of section or unit is used by varying the nuinber of sections that go into the element. Provision is niadeby the use of the lug l5 whereby the heating coil may be alternated without loss of efficiency, It is of course obvious that the heating element maybe used in any position, andthis is a great advantage iii ovens and broilers where it is desirable to use the heating elementl in an inverted position. It is not necessary in this element to fasten the heating coils to the insulating base, that is, to the slab, by screws, nails, or other means, as the heating coils are held firmly in place by the sections Even ldistribution of heat is f themselves. obtained for high, low, or medium heats, by operating the switch so that alternate coils only are used on medium heat, all the coils in series on low heat, and two sets of half the coils, the coils of each set being in series, \on a high heat, the coils of one series being in parallel to the coils of theother series.

W'hile we have illustrated certain details of construction and arrangement of parts which have been found most eiiective 'in practice, we do not wish to be limited to these details or arrangements as it is obvious that many changes might be made without departing from the spirit of the invention.

Having described the invention, what is claimed is:

1. An electric heating'element comprising a plurality of conjoined units-of non-conducting material having interlocking engagement with each other, and formed to provide coil receivingchannels.

2. An electric heating element comprising a plurality of conjoined units ot non-conducting material, each unit having longitudinal grooves disposed on its opposite faces which, when the units are conjoined, pro- .vide longitudinally extending coil channels.'

3. An electrical heating element comprising a series of conjoined units, each unit having oppositely disposed longitudinally extending grooves in its opposite faces which, when the units are conjoined, provide longitudinally extending coil.channels, and each unit having notches on its side faces intersecting the grooves, which, when the units are conjoined, provide heat radiation openings.

4. An electrical heating element compris- Ving a plurality of conjoined units, each. unit having oppositely disposed grooves in its faces which when the-units are conjoined provide longitudinally extending coil channels and each unit being provided on its ends with projecting non-conducting conductor supporting lugs smaller in cross section jthan the cross section ot the units.

' 6,. An electrical heating element comprising a plurality of conjoined units of nonconducting material, each unit having oppositely disposed longitudinal grooves in its side faces which when the unitsare conjoined rovide longitudinally extending coil v VV*channe s, each unit having notches on its side faces intersecting the grooves which when the unitsare conjoined provide radiation openings, each unit being formed on one side face with recesses an'd on the opposite side face with projecting dowels corresponding to the recesses which when the units are conjoined engage with each other to thereby hold the units lin alineinent, and each unit at its ends being formed with projecting lugs smaller in cross section than the cross section of the units ing a series ot conjoined units, each unit' 7. A unit for electrical 'elements formed oi' an elongated block ot'n'Dn'scoh--, ducting material, the side faces ot the blbk being formed with longitudinally extending j grooves whereby when a plurality ot the units are conjoined coil channels shail he provided, the side faces of each unit beine' formed with vertically extending notches intersecting the coii channels to form radiationr aan joined.

8. A. heating element of non-conducting material having a plurality of coil channels extending through itin parallel relation, the end faces of the heatingjelement being provided with outwardly projectinglugs disposed between the' coil channels, heating coils disposed in the coil channels, alternate coils being connected alternately at opposite ends of the heating element by wires passing on one side 'of said lugs, the other coils'being connectedat opposite ends by wires passing on the other side of said lugs, means whereby one coil of each set of coils may be connected to a source of current anda return openings when a plurality of units are conf conductor common to both sets of coils, and l means whereby current may be directed into A all of saidcoils in series or into the sets of coils in parallel.

9;. el unit for electrical heating elements comprising a solid bar of nonfconducting material having longitudinal grooves on opposite side faces whereby when two of said units are conjoined the grooves shall define al longitudinally extending coil channel.

10. A. unit for electrlcal heating elements comprising a solid bar of non-'conducting material having longitudinal grooves on opposite side faces, said -grooves extending from end to end and opening upon the end faces of the bar whereby when a pluralityy of units are conjoined the grooves will define a plurality of longitudinally extending coil channels opening' upon the end faces of the element so formed.

11. A unit for electrical heating elements comprising' a solid bar of non-conducting material having longitudinal grooves on opposite side faces whereby when a plurality of units are conjoined the grooves will-define a plurality lof longitudinally extending coil channels, said bar at its ends being formed with projecting integral lugs .spaced from. the faces of the bar. l

12. A unit for electrical heating elements comprising a solid bar of non-conducting material having longitudinal grooves on opposite side faces whereby when a plurality of units are conjoined the grooves will define a plurality of longitudinally extending coil channels, the bar being formed upon the grooved faces with means whereby it may be int'erlocked with an adjacent bar.

13. il. unit for electrical heating elements comprising a solid bar of non-conducting material having longitudinal grooves on opposite side faces whereby when a plurality of units are conjoined t'he grooves will define a plurality of longitudinally extending' coil channels, the bar being formed upon one of its grooved faces with recesses and on the opposite grooved face with projections dispose in alinement 'ith said recesses whereby the and lugs extending out at spacedintervals from said rib on opposite faces thereof and spaced from the base, the outer end faces of said lugs being in the same plane as the ed'e face of the base. j

15. .1.5i unit for electrical heating elements comprising a solid bar `of non-conducting material, said bar having a relatively wide base, a medially disposed rib extending right angles from the base and tapering transversely from the base, and integral lugs extendingl out at spacedintervals from the rib on opposite faces thereof and spaced from the base, the end faces of the lugs and the edge face of the base being in the same plane.

16. A unit for electrical heating elements comprising a solid bar of non-conducting edge face of the base being in the same plane,

one edge face of the base being formed with recesses and the opposite edge face with projections disposed in alinement with the re cesses. f

17. lin electrical heating element formed of a plurality of units of non-conducti`ng material, the units being formedto provide a plurality of longitudinally extending coil channelsthrough the heating element and provide heat radiating openings extending from one face of the element into and intersecting said coil channels, said units abutting against each other to prevent thev radiation of heat ercept through said heat radiating openings.

18. 4The combination with' an electrical heating element comprising a series of con,- joined units and heating coils inclosed-in said units, of a base of nonsconducting mate rial having a recess in which the units are disposed, said recess being square and having an area equal to the area of the heating element formed by the conjoined units to thereby hold the units in engagement with each other, the recess being' formed with a shoulder upon which the margin of the heatling'element rests to thereby provide a dead airspace below the heating element.

419. lli heating element of non-conducting man end facesvof the heat'ing element beingrproon'f'eivgnetures in the presence of tvi'o witvded with outwardlyprojecting lugs dsnesses.

" sed between the coil channels, said lugs f .seing lessin thicknessthan the thickness of y 5 the heating element and havngea WidthA not'l L Y greater vthan the `distance between the adja- 'WtnSeS-;. l

cent 4Walls of adjacent coil channels. CQLINFQHARDY, 

